[Serusers] Rewriting "From" / Setting caller number for PSTN calls

Hi, with an usuall SER setup a typical user account looks like this: Primary sip address: sip:joe@myvoip.net Aliases: Berlin incoming number: sip:493042423@myvoip.net Los Angeles "" : sip:1310232323@myvoip.net If "joe" now calls out via a PSTN-GW the caller-id which is transmitted to the PSNT-GW would be "joe". Now "Joe" is clearly alphanumeric and no PSTN-GW (or the PSTN-Switch to which the PSTN-GW is connected) will accept "Joe" as caller-id. All i can currently do is setting a default callerid on the PSTN-GW in case the incoming caller-id isnt valid. What i would like to do though is to lookup if a user has an alias for a certain region and rewrite the the from line in the sip-packet going to the PSTN-GW. Example: "Joe" uses the Berlin/german PSTN-GW or dials a german PSTN number. Now i would look into the alias table and search for either an alias starting with "49" or "4930" and if one is found set the from field to the according alias. In this case "493042423(a)myvoip.net".net". This would ensure that, if possible, a matching caller-id would be set for every user. Problems: - "From" line rewriting is not RFC compliant. - I dont see any possebility to do this with the stock SER software Questions: - Which module would be a good starting point for adding this functionality? All which would be needed would be one command for looking up the alias list of a user from memory using regular expressions. - How do others cope with this problem? The easy but not very elegant solution is to just use a valid e.164 number (ex. the LA number) as primary sip address. But that still doesnt fix the problem that "Joes" Los Angeles number would be set as caller-id even if he got a valid "berlin" number too and calls via a german PSTN termination. best regards, Arnd